JAMB UTME - Physics - 1988 | Green Bridge CBT

Question 1 Report

A piano wire 0.5m long has a total mass of 0.01kg and is stretched with a tension of 800N. Calculate the frequency of the wire when it sounds its fundamental note

200Hz

100Hz

4Hz

2Hz

Answer Details

F =

\frac{1}{2 L}

\sqrt{\frac{T}{m}}

N:B m is mass per length

= $\frac{0.01}{0.5}$

= 0.02kgm-1

F = $\frac{1}{2 \times 0.5}$ $\sqrt{\frac{800}{0.02}}$

= 200Hz

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Read lesson note on Elasticity (JAMB)

Work, Energy & Power

Elasticity

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Question 2 Report

When a resistance R is across a cell, the voltage across the terminals of the cell is reduced to two-third of its normal value. The internal resistance of the cell is

\frac{2}{1}

R

\frac{1}{2}

R

\frac{3}{2}

R

5R

Answer Details

IR =

\frac{2}{3}

I(R + r)

r = $\frac{1}{2}$ R

Read lesson note on Current Electricity (JAMB)

Read lesson note on Scalars And Vectors (JAMB)

Current Electricity

Scalars And Vectors

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Question 3 Report

Two strings of the same length and under the same tension gives notes of frequencies in the ratio 4 : 1. The masses of the strings are in the corresponding

2 : 1

1 : 2

1 : 4

1 : 16

Answer Details

F =

\frac{1}{2 L}

\sqrt{\frac{T}{m}}

$\frac{F_{1}}{F_{2}}$ = $\sqrt{\frac{m_{2}}{m_{1}}}$

$\frac{1}{4}$ = $\sqrt{\frac{m_{2}}{m_{1}}}$

$\sqrt{\frac{m_{2}}{m_{1}}}$ = $\frac{1}{2}$

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Motion

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Question 4 Report

A household refrigerator is rated 200 watts. If electricity costs 5k per kWh, what is the cost of operating it in 20 days?

N4.80

N48.00

N480.00

N4800.00

Answer Details

Energy(kWhr) = 200 x 10-3 x 20 x 24

= 96kwhr

1 kwhr cost 5 kobo ; 96 kwhr will cost

5 x 96 = 480 kobo

Read lesson note on Electrical Energy And Power (JAMB)

Read lesson note on Electromagnetic Field (Part 1) (WAEC)

Electrical Energy And Power

Electromagnetic Field (Part 1)

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Question 5 Report

Which of the following ammeters may be used to measure alternating currents? i. moving-coil ammeter ii. moving-iron ammeter iii. hot-wire ammeter

i and ii only

ii and iii only

i and iii only

i, ii, and iii

Capacitors

Electrostatics

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Question 6 Report

In the figure above, what is the angle of reflection of the ray of light at mirror M?

90∘

60∘

45∘

30∘

Electrostatics

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Question 7 Report

When heat is applied to one end of a metal rod, the molecules at the other end soon begin to vibrate with greater amplitude than before because heat has been transferred by

radiation

convection

conduction

evaporation

Heat Transfer

Simple A.C Circuits

Conduction Of Electricity Through

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Question 8 Report

A dynamo primarily combines

mechanical energy into electrical energy

electrical energy into kinetic energy

potential energy into kinetic energy

kinetic energy into potential energy

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Question 9 Report

A slight loading of a tuning fork has the effect of

decreasing its amplitude

increasing its amplitude

decreasing its frequency

increasing its frequency

Newton’s Laws Of Motion

Simple Harmonic Motion

Motion

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Question 10 Report

Which of the following phenomena explains the formation of a mirage? i. Reflection ii. Refraction iii. Diffraction

i and ii only

ii and iii only

i and iii only

i, ii, and iii only

Reflection Of Light At Plane And Curved Surfaces

Refraction Of Light Through Plane And Curved Surfaces

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Question 11 Report

A force, 10N, drags a mass 10kg on a horizontal table with an acceleration of 0.2ms. If the acceleration due to gravity is 10ms-1, the coefficient of friction between the moving mass and the table is

0.02

0.08

0.20

0.80

Answer Details

μ

mg = ma

$μ$ x 10 x 10 = 10 x 0.2

$μ$ = 0.02

Read lesson note on Newton’s Laws Of Motion (WAEC)

Read lesson note on Measurements And Units (JAMB)

Newton’s Laws Of Motion

Measurements And Units

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Question 12 Report

When one arm of a U-tube manometer is connected to a gas supply, the levels of mercury in the two arms of the U-tube is shown in the figure above, if the atmospheric pressure is 76.0cm hg, the gas pressure is

62.6cm hg

72.5cm hg

79.5cm hg

85.9cm hg

Measurements And Units

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Question 13 Report

E, F and G are yellow, red and cyan transparent light filters respectively. The color of a white opaque object when viewed through the arrangement of the filters above is

yellow

red

black

blue

Structure Of The Nucleus

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Question 14 Report

The product PV where P is pressure and V is volume has the same unit as

force

power

energy

accelaration

Answer Details

PV =

\frac{N}{m^{2}}

x

\frac{m^{2}}{1}

= Nm

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Measurements And Units

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Question 15 Report

Which of the following symbolic representations is correct for an atom X with 22 electrons and 43 neutrons?

43	X
22

22	X
43

_{43}^{65} X

_{22}^{65} X

Structure Of The Atom (Nigeria Only)

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Question 16 Report

A note is called an octave of another note when

its frequency is twice that of the first note

its frequency is half of the first note

the notes have the same fundamental frequency

its periodic time is twice that of the first note

Sound Waves

Propagation Of Sound Waves

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Question 17 Report

How long will it take a 60kg man to climb a height of 22m if he expended energy at a rate of 0.25kW. [g = ms-2]

5.3s

34.5s

41.6s

52.8s

Answer Details

power = mgh

0.25 x 103 = $\frac{60 \times 10 \times 22}{t}$

t = 52.8 sec

Read lesson note on Work, Energy And Power (WAEC)

Work, Energy And Power

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Question 18 Report

When white light is dispersed by a spectrometer, the component having the shortest wavelength is

orange

green

violet

red

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Question 19 Report

The wire X in the figure above is at right angles to the plane of the paper and carries a current into the paper. at which of the points labelled 1-4, will the magnetic flux density due to this current be in the same direction as that of the horizontal component of earth's magnetic field

1

2

3

4

Newton’s Laws Of Motion

Electromagnetic Field (Part 2)

Gravitational Field

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Question 20 Report

The principle of operation of an induction coil is based on

Ohm's law

Amphere's law

Faraday's law

Columbs law

Electric Field

Properties Of Waves: Reflection, Refraction, Diffraction

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Question 21 Report

The figure above shows displacement-time graphs for three different motions. which of the following statements is correct

graph 2 corresponds to the highest velocity

graph 1 corresponds to zero gravity

graph 3 corresponds to a particle moving in the negative x direction

graph 2 corresponds to a particle moving in the positive x direction

Scalars And Vectors

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Question 22 Report

The figure above shows two waveforms X and Y. If the frequency of X is 30Hz what is the frequency of Y

12Hz

19Hz

60Hz

75Hz

Propagation Of Sound Waves

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Question 23 Report

Which of the following quantities are scalars? i. Electrical potential ii. Torque iii. Momentum iv. Kinetic energy

ii and iii only

i and ii only

iii and iv only

i and iv only

Scalars And Vectors

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Question 24 Report

In the circuit diagram above, the ammeter reads a current of 3A when R is 5 ohms and 6A when R is 6 ohms,the value of the unknown resistance X is

1

2

3

4

Scalars And Vectors

Simple A.C Circuits

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Question 25 Report

The figure above shows three different ways of hanging a heavy picture from a hook. the tension in the string will be

Greatest in X

Greatest in Y

Greatest in Z

Same in each one

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Question 26 Report

A particle is injected perpendicularly into an electric field, it travels along a curved path as depicted in the image above,the particle is

gamma ray

electron

neutron

proton

Electric Field

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Question 27 Report

Which of the following are the correct SI units of the quantities indicated? i.N(Force) II. Mn-1 (Torque) iii. watt(Power) iv. kgms-2

i and ii only

i, ii and iii only

i, ii, and iv only

i and iii only

Position, Distance And Displacement

Measurements And Units

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Question 28 Report

A lorry travels 10km northwards, 4km eastwards, 6km southwards, 4km westwards to arrive at a point T. What is the total displacement?

6km south

4km north

6km north

4km east

Scalars And Vectors

Position, Distance And Displacement

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Question 29 Report

Which of the following factors affects the speed of sound in air? i. Temperature ii. pressure iii. Frequency

i only

ii only

i and ii only

ii and iii only

Description Property Of Fields

Electromagnetic Field (Part 2)

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Question 30 Report

The speed of sound in air at sea-level is 340ms-1 while that of light is 300 000kms-1. How far (to the nearest meter) from the center of a thunderstorm is an observer who hears a thunder 2s after a lightening flash?

170ms-1

340ms-1

600ms-1

680ms-1

Answer Details

Distance = 340 x 2 = 680ms-1

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Current Electricity

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Question 31 Report

Two forces whose resultant is 100N, are at right angle to each other. If one of them makes an angle 30o with the resultant, determine its magnitude.

8.66N

50.0N

57.7N

86.6N

Answer Details

COS 30o =

\frac{F_{1}}{100}

F1 = 86.6N

Read lesson note on Scalars And Vectors (WAEC)

Scalars And Vectors

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Question 32 Report

A cell of internal resistance 2 ohms supplies current to a 6 ohms resistor. The efficiency of the cell is

12.0%

25.0%

33.3%

75.0%

Answer Details

Efficiency =

\frac{I R}{I (R + r)}

x 100

= $\frac{6}{I (2 + 6)}$ x 100

= 75%

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Current Electricity

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Question 33 Report

A spectrum of sunlight is said to be impure when

it is made of only three colours

it has no red colour in it

the different colours in it overlap

it does not contain white light

Light Waves

Properties Of Waves: Reflection, Refraction, Diffraction

Electromagnetic Field (Part 2)

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Question 34 Report

When taking a penalty kick, a footballer applies a force of 30.0N for a period of 0.05s. if the mass of the ball is 0.075kg, calculate the speed with which the ball moves off.

4.50ms-1

11.25ms-1

20.00ms-1

45.00ms-1

Answer Details

F =

\frac{m (v - u)}{T}

30 = $\frac{0.75 (v - 0)}{0.05}$

v = 20ms-1

Read lesson note on Equilibrium Of Forces (WAEC)

Equilibrium Of Forces

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Question 35 Report

An object is placed 10cm in front of a concave mirror of focal length 15cm. What is the position and nature of the image formed?

30cm and virtual

6cm and real

6cm and virtual

30cm and real

Answer Details

F =

\frac{u v}{u + v}

15 = $\frac{10 \times v}{10 + v}$

v = -30cm

Read lesson note on Electrostatics (JAMB)

Electrostatics

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Question 36 Report

A body whose mass is 2kg and has a volume of 500cm just floats when completely immersed in a liquid. Calculate the density of the liquid

4.0 x 102kgm-3

4.0 x 103kgm-3

1.0 x 103kgm-3

1.0 x 106kgm-3

Answer Details

since the object floats, density of liquid = density of object

D = $\frac{m}{v}$

= $\frac{2}{500 \times 10}$

= 4.0 x 103kgm-3

Read lesson note on Pressure (JAMB)

Pressure

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Question 37 Report

Which of the following statement is TRUE of ultraviolet, visible and infra-red rays?

they are all electromagnetic waves with the same wavelength

ultra-violet rays have shorter wavelengths than infra-red rays and produce flourescence

infrared rays have shorter wavelength than visible light and produce the sensation of heat

the wavelenghts increase in the sequence: visible, ultra-violet, infra-red

Sound Waves

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

Light Waves

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Question 38 Report

A 20-toothed gear wheel drives a 60-toothed one. If the angular speed of the smaller wheel is 120 rev s-1, the angular speed of the larger wheel is

3 rev s-1

40 rev s-1

360 rev s-1

2400 rev s-1

Answer Details

\frac{speed of driver}{speeder driven}

=

\frac{no. of teeth of driver}{no. of teeth of driven}

$\frac{120}{V}$ = $\frac{20}{60}$

v = 360 rev s-1

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Read lesson note on Mass And Weight (WAEC)

Motion

Mass And Weight

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Question 39 Report

Which of the following properties is/are common to all waves? i. Diffraction ii. Refraction iii. Interference

i only

ii only

ii and iii

i, ii, and iii

Properties Of Waves: Reflection, Refraction, Diffraction

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Question 40 Report

Which of the following media allow the transmission of sound wave through them i. Air. ii. Liquids. iii. Solids.

i and ii only

i and iii only

ii and iii only

i,ii and iii

Reflection Of Light At Plane And Curved Surfaces

Propagation Of Sound Waves

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Question 41 Report

The amount of heat needed to raise the temperature of 10kg of copper by 1k is its

specific heat capacity

heat capacity

latent heat

internal energy

Heat Energy

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Question 42 Report

A particle starts from rest and moves with a constant acceleration of 0.5ms-2. The distance covered by the particle in 10s is

2.5m

5.0m

25.0m

50.0m

Answer Details

X = ut +

\frac{1}{2}

at

= (0 x 10) + ( $\frac{1}{2}$ x 0.05 x 10 x 10)

= 25m

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Motion

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Question 43 Report

In a certain fusion reaction, a deuteron (${}^{2}_{1}\mathrm{H}$) interacts with a triton (${}^{3}_{1}\mathrm{He}$) and produces an a-particle (${}^{4}_{2}\mathrm{He}$) and a second product. The second product is

a proton

an electron

a neutron

a gamma ray

Answer Details

_{1}^{2} H

+

_{1}^{3} H

\to

_{2}^{4} H e

+

_{0}^{1} H e

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

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Question 44 Report

To obtain a magnification of 2.5, how far should an object be placed from the pole of a thin converging lens of focal length 10.20m?

0.13m

0.25m

0.28m

0.50m

Answer Details

v = 2.5u

F = $\frac{u v}{u + v}$

0.2 = $\frac{u \times 2.5 u}{u + 2.5 u}$

u = 0.28m

Read lesson note on Reflection Of Light At Plane And Curved Surfaces (JAMB)

Read lesson note on Simple A.C Circuits (JAMB)

Read lesson note on Electrostatics (JAMB)

Reflection Of Light At Plane And Curved Surfaces

Simple A.C Circuits

Electrostatics

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Question 45 Report

A tap supplies water at 25oC while another supplies water at 75oC. If a man wishes to bathe with water at 40oC, the ratio of the mass of cold water to the mass of hot water required is

1 : 3

15 : 8

7 : 3

3 : 1

Answer Details

Heat lost = heat gained

mh x c x (75 - 40) = mc x c x (40 - 25)

$\frac{m_{h}}{m_{c}}$ = $\frac{35}{15}$

= $\frac{7}{3}$

Read lesson note on Heat Energy (WAEC)

Heat Energy

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